The group A streptococci, Streptococcus pyogenes, are responsible for a wide variety of human diseases. Infections by these organisms of the pharynx, skin, and soft tissues can range from superficial to severe invasive infections. Additionally, these organisms can result in the post- infection sequelae of rheumatic fever and acute glomerulonephritis. In the pst several years in the United States, there have been outbreaks of rheumatic fever, streptococcal toxic shock syndrome, and this year, necrotizing fascitis. Although some effort has been directed at understanding the genetic basis for the virulence of this organism, there are large gaps of information remaining concerning the role of many of the proposed determinants of virulence in human disease. Additionally, little is known about tahe physiology of this organism and factors which enhance its growth and allow it to be established in a host. For this reason it is essential to know as much as possible about the organism itself, including its complete repertoire of genes and overall chromosome organization. The goal of this proposal is to determine the complete DNA sequence of the genome of Streptococcus pyogenes. An M1 serotype (class I), rheumatogenic strain that was originally isolated from a patient with severe invasive disease, has been selected as the prototype strain to be employed in these studies. We have recently constructed the first physical and genetic map of the chromosome of this strain. With a genome size of approximately 2,000 kilobases, the technology is in place to accomplish such a goal in a relatively short period of time. Such a concerted effort promises to be cost effective, but more importantly will provide essential information to the scientific community which will facilitate future work and allow investigators to focus on the more important questions relating to virulence and physiological factors associated with disease. In addition to elucidating the basic genetics of this organism, information from this study will also facilitate the development of antibiotic drugs capable of specifically interfering with newly identified genes and their proteins as well as genes encoding antigens that could be used in vaccines. Finally, the results from this study will provide important information for future studies of gene regulation, chromosome structure and organization, and evolutionary relationships with other organisms. This study will be done as an interactive research grant with a similar analysis being done on the Neisseria gonorrhoeae genome, another organism of great medical importance. A sequencing core with substantial capability and expertise will be the final component of this IRPG. This assembly of scientists and facilities should allow interchange of technique, materials, ides, and data. The comparison of sequence information and organization between Gram positive and Gram negative cocci associated with infectious diseases should provide new insights of differences and similarities of these organisms as well as into their evolution.